Structural improvement of long board of swim fin

ABSTRACT

An improved structure of a long board of a swim fin does not use a plate in gradually changing thickness, but rather uses a fiberboard in fixed thickness. The fiberboard is provided with at least a first opening and at least a second opening arranged in line from small size to large size. The first opening can be triangular, and the second opening can be n-shaped, so that the mechanical strength of fiber flat plate changes gradually from one end to the other end. The plate effective thickness is changed gradually without time consuming processing technique. As such, the manufacturing time and cost are reduced, and consistent manufacturing quality is maintained.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

Not applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

REFERENCE TO AN APPENDIX SUBMITTED ON COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates generally to a long board of swim fin, and more particularly to an improved structure of the long board of a swim fin which does not use the specification plate in gradually changed thickness, but uses a planar fiberboard to fabricate a series of openings to reduce the fabrication time and cost.

2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98

At present, a lot of seashore recreational activities are popular. In some seashore recreational activities, the user wears swim fins for paddling in the water. In order to increase the paddling efficiency, the long board of the swim fin shall be flexible, which is to say, the part near the user's foot must be harder than the front end of the long board of swim fin, so that the front end of the long board of swim fin can be bent when the user is paddling, and the long board of the swim fin can paddle efficiently. Therefore, in order to manufacture a flexible long board of swim fin, it is known to make a plate in gradually changing thickness, as is the case with the known long board A shown in FIG. 1. As can be seen, the thickness of the long board of swim fin increases gradually from the front end to the back end. In other words, the strength of the known long board A decreases from the front end to the back end, so that there is enough flexibility to increase the paddling efficiency. Therefore, the plates produced in bulk, normalized and in uniform thickness cannot be used directly, the plates in uniform thickness have worse flexibility, the manufacturing technique of specification not only prolongs the fabrication time of long board of swim fin, but also increases the money cost, and it is difficult to control the manufacturing quality.

In view of this, the present inventor accumulated related studies and practical experience over years, and created an improved structure of the long board of swim fin, so as to remedy the deficiencies in the aforesaid known technology.

BRIEF SUMMARY OF THE INVENTION

The primary object of the present invention is to provide an improved structure of the long board of swim fin, such that the processing time and cost of the long board of swim fin can be reduced.

In order to attain said object, the structural improvement of the long board of swim fin of the present invention does not use the known specification plate in gradually changing thickness as the long board of swim fin, but uses a fiber flat plate in fixed thickness, which can be a glass fiber board or a carbon fiber board, and the fiber flat plate is provided with at least a first opening and at least a second opening arranged linearly from small size to large size. The first opening can be triangular, the second opening can be n-shaped, and the first opening and the second opening can be the same pattern and arranged in the order of size, so that the mechanical strength of fiber flat plate can change gradually from one end to the other end, the flexibility of fiber flat plate is increased without time consuming processing technique to gradually change the plate thickness, so as to reduce the manufacturing time and cost and to maintain a certain manufacturing quality.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is the side section view of the known long board of swim fin.

FIG. 2 is the stereogram of the present invention.

FIG. 3 is the sectional view of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 2 and 3 disclose the implementation method of the present invention. The aforesaid figures describe the structural improvement of the long board of swim fin of the present invention. The main body 1 is a flat plate, which can be a fiberboard, e.g., glass fiber board or carbon fiber board. Features: the main body 1 has at least a first opening 2 and at least a second opening 3; the first opening 2 and the second opening 3 can be arbitrary geometry. In this embodiment, the first opening 2 is triangular, the second opening 3 is n-shaped, the first opening 2 and the second opening 3 can be the same pattern but of different sizes. The first opening 2 and the second opening 3 are arranged in alignment. This embodiment uses one first opening 2 and six second openings 3, but not limited to this. There is a first spacing 4 between the first opening 2 and the second opening 3, there is a second spacing 5 between every two second openings 3; the second openings 3 are arranged according to size. The opening near the user's foot is the smallest, the opening near the front end of the long board of swim fin is the largest. If a plurality of first openings 2 is used, the first openings 2 are arranged according to size, the opening near the user's foot is the smallest, the opening near the front end of the long board of swim fin is the largest, and there is a spacing between every two first openings 2.

As the front end of the present invention has the largest opening, tapering to the other end, the front end of the present invention has the lowest strength, increasing to the other end. In the embodiment of the present invention, the strength of the long board of swim fin changes gradually due to the gradually changed openings, so that the long board of swim fin is flexible. Therefore, the front end of the present invention can be bent when the user paddles with the swim fin, the user's paddling efficiency is increased, meeting the paddling performance requirement. The first spacing 4 and the second spacing 5 can be adjusted according to the shape and quantity of the first opening 2 and the second opening 3. A triangular first opening 2 and six n-shaped second openings 3 are used in this embodiment, small first spacing 4 and second spacing 5 are preferred, the present invention has appropriate softness and can paddle to go forward. The first spacing 4 and the second spacing 5 can be adjusted according to the raw fiberboard strength.

The present invention can be made by using the commercially available normalized fiberboard, e.g. glass fiber board or carbon fiber board, the normalize fiberboard has low price and good and consistent quality. In the machining process of the present invention, the first opening 2 and the second opening 3 are incised in the fiberboard, the other appearance processing procedures are omitted, not like the known long board of swim fin that a plate in gradually changed thickness shall be fabricated according to specification, the fabrication takes time, small volume fabrication is available only, the manufacturing cost is high, and it is difficult to control the quality. Therefore, the present invention can reduce the production cost of the long board of swim fin, and can unify the quality of products.

Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

I claim:
 1. An improved structure of the long board of a swim fin, comprising a flat plate, wherein the flat plate has at least a first opening and at least a second opening.
 2. The structure defined in claim 1, wherein the first opening and the second opening are arranged in alignment.
 3. The structure defined in claim 2, wherein there is a first spacing between the first opening and the second opening.
 4. The structure defined in claim 3, wherein the first opening is triangular.
 5. The structure defined in claim 2, wherein there is a plurality of second openings, and there is a second spacing between every two second openings, the second openings are arranged in ascending order of size.
 6. The structure defined in claim 5, wherein the second opening is n-shaped. 